Proposed Environmental Impacts of the Gallipolis Locks and Dam Replacement, Ohio River Mile 279.2, on the Benthic Macroinvertebrates and Fishes of Flatfoot Creek, Mason County, West Virginia

The Gallipolis Locks and Dam at Ohio River Mile 279.2 is soon to be modified or replaced. Construction in the area will effect the lower portion of the small drainage basin (14.61 km) of Flatfoot Creek. Depending on the action taken, a large proportion of Flatfoot Creek and/or a tributary of Mud Run will have severe ecological alterations. For this reason, Flatfoot Creek was investigated for water quality, benthic macroinvertebrates, fish populations and the feeding requirements of the fishes. A physio-chemical analysis was made of Flatfoot creek. With the exception of five parameters, the creek met guidelines set by state and Federal agencies. The most important limiting factors of the tailwaters were low dissolved oxygen (1.0 mg/1) and high total solids (652 mg/1). The benthic populations ranged from a low species diversity (d = 0.36) at the tailwaters to the highest value (d = 3.04) at the headwaters. Dipteran larvae and aquatic oligochaetes inhabited the lower reaches while ephemeropterans, plecopterans, and trichopterans inhabited the upper reaches. No rare, threatened or endangered species of benthic macroinvertebrate was found in the study area. The fishes of Flatfoot Creek were dominated by forage species (e.g. Emerald Shiner, Striped Shiner and Creek Chub). The rough fishes and game fishes comprised a small portion of the specimens. Important among the rough fishes were the White Sucker, Black and Yellow Bullheads. Game fishes were predominantly Green Sunfish, Bluegill, Black Crappie, and Longear Sunfish. The Southern Redbelly Dace and the River Shiner are listed as fishes of scientific interest on the tentative list of rare animal species for West Virginia. Stomach analysis showed a large portion of the fish populations to be dependent upon benthic organisms, to the extent that fishes would not inhabit the area unless sufficient benthic populations were present. Recommendations were made to the U.S. Army Corps of Engineers for disposal of dredge material from the canal they propose to construct. The author feels uniform disposal over the bottomlands of Flatfoot Creek with the stream re-channeled will have the least detrimental effect on the environment. Ecological requirements such as pool and riffle habitats with proper substrate material will allow benthic and fish populations to populate the man-made portion of the stream